The groove is straight and funky, hence the name Straight Minor. We're also not using any 7s or 9s in our minor riff. Some of these examples are indeed more riff based. I made them this way to sneak in some cool pentatonic licks in the holes of our rhythm playing. Vibe is a very important thing here as well. I'll explain how you can play a riff like this in a tune without being obtrusive.